1. Technical Field
The present disclosure relates to a cutting apparatus in which a cutting blade and an object to be cut are moved relative to each other so that the object is out into a desired shape.
2. Related Art
There has conventionally been known a cutting plotter which automatically cuts a sheet such as paper, for example. The sheet is affixed to a base material serving as a holding member having an adhesive layer on a surface thereof. The cutting plotter includes a drive mechanism having a pair of rollers which are vertically disposed and hold both ends of the base material therebetween so that the object is moved in a first direction. The cutting apparatus also includes a cutter holder which supports a cutting blade and is moved in a second direction perpendicular to the first direction, whereby the sheet is cut.
FIG. 11 schematically illustrates a commonly-used cutter (a cutting blade) 100 and a cutter holder 101 both employed in conventional cutting plotters. As shown, the cutter 100 is fixed to a lower end of a bar-like cutter shaft 102 by a screw 103. The cutter shaft 102 is mounted on a bearing 101 so as to be rotatable about an axis O. The bearing 104 is provided in a recess 101a formed in a lower end of the cutter holder 101. The cutter 100 includes a blade portion 100a which is located so that a lowermost end blade edge 100b thereof is offset by distance d relative to the axis O. Accordingly, when the sheet 105 is cut by the cutter 100 with the movement of the cutter 100 and the sheet 105 relative to each other, the blade edge 100b of the cutter 100 is subjected to resistance (reactive force) such that the cutter shaft 102 is rotated about the axis O. More specifically, the direction of the blade edge 100b of the cutter 100 is automatically changed according to a direction in which the cutter 100 and the sheet 105 are moved relative to each other.
The resistance to which the blade edge 100b of the cutter 100 is subjected is rendered large when cutting is executed by the cutting plotter. In order that the load applied to the cutter 100 may be rendered smaller for improvement in the sharpness of the cutter 100, an angle α between the blade 100a of the cutter 100 and the sheet 105 has been suggested to be set to a small value.
On the other hand, when a cutting line of the sheet 105 includes a corner, which is cut by the cutter 100, the cutter 100 is rotatively moved so as to slightly pry or twist a distal end of the corner, whereby the direction of the blade edge 100b is changed. Accordingly, the angle α is desirable to be set to a large value. Thus, the cutter 100 has conflicting advantages and disadvantages when the angle α is set to both a small value and a large value, respectively. It is desirable to simultaneously overcome the disadvantages in the two cases.